Touring - touring bike sizing

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View Full Version : touring bike sizing


Phatman
03-28-04, 02:49 PM
I am seriously contemplating buying a touring bike. for a long time, I have been building up this old bianchi that I got from my grandad who won it in a raffle contest back in the day. It was once equipped with mid-range suntour (about equivilent of tiagra or 105 back then). anyway, I have put a new triple crank, new bars, XT rear mech, and I put my old 32 hole bulletproof matrix rims on it from my lemond (I bought a new wheelset for the lemond)

I have learned a lot about bike maintence from this old bianchi, however, I have several problems with it:
-no rack bosses or waterbottle bosses. This was a "sport tourer" from the 1980s. In other words, it was never meant to go touring.
-Its a pinch too small
-The bike was designed for 27'' wheels, and the matrix rims I put on there are 700c. it had long-reach brakes already so that fenders would fit for 27''ers. Btw, these particular brakes SUCK...
-I don't quite trust it...its a bit jury-rigged, becuase year 2003 components don't like 1982 frames...

Anyway, I think I might convert it to a fixe for riding to work this summer. I'll put the old crank back on and see if I can find a 27" fixie wheel. but thats a matter for the fixie forum.

Back to the touring bike. I was thinking that I might like to do some 2-7 day tours, and I think I might like something like a jamis nova or maybe some other light tourer, but I just want a frame...I have a bunch of parts on the bianchi I can swap over.

The real question is one of size. I have a lemond alpe d'huez that I absolutely love. the geometry fits me perfectly. Its a 57 cm, with a 57.5cm top tube and a 120mm flat stem. My bars are about 2-2.5 inches below the seat.

I suspect that with a touring bike, I'd want the bars about level with the seat (that just seems to be the concensus on this particular forum, I've never had the bars level), however, I have never had back trouble on the lemond, even on 50+ mile rides. what should the reach be like in comparison to the lemond? should I get a slightly shorter top tube? a slightly longer one?


Frith
03-28-04, 03:40 PM
I wouldn't stray too far from the lemond setup if I were you. Keep in mind though that top tube isn't the only thing you should be thinking about. Many touring bikes or even light/sport tourers have slacker seat tube angles. This means that in order to get your saddle in the right place relative to the bottom bracket you may have to move it forward slightly, effectively shortening your top tube. Every degree of difference is about a cm of top tube once you've made your adjustments.
If for instance your lemond has a 73.5 degree STA and a 57.5 TT
and the tourer you're looking at has a 72.5 STA and a 57.5 TT
You're going to need to move your saddle forward about 1cm to get the right pedal stroke that you're used to on your lemond. This makes your reach 1cm less, nessesatating the need for a 130mm stem (which is on the long side of ideal)Compounded is the fact that tourers have slacker head tube angles and higher bars shortening your reach even more (perhaps about 1 more cm).
I would say make sure you compare the angles of any bike you are thinking of getting with your lemond. you may need to go about 1-2 cm longer. You may not need to go longer at all.

Phatman
03-30-04, 03:16 PM
I wouldn't stray too far from the lemond setup if I were you. Keep in mind though that top tube isn't the only thing you should be thinking about. Many touring bikes or even light/sport tourers have slacker seat tube angles. This means that in order to get your saddle in the right place relative to the bottom bracket you may have to move it forward slightly, effectively shortening your top tube. Every degree of difference is about a cm of top tube once you've made your adjustments.
If for instance your lemond has a 73.5 degree STA and a 57.5 TT
and the tourer you're looking at has a 72.5 STA and a 57.5 TT
You're going to need to move your saddle forward about 1cm to get the right pedal stroke that you're used to on your lemond. This makes your reach 1cm less, nessesatating the need for a 130mm stem (which is on the long side of ideal)Compounded is the fact that tourers have slacker head tube angles and higher bars shortening your reach even more (perhaps about 1 more cm).
I would say make sure you compare the angles of any bike you are thinking of getting with your lemond. you may need to go about 1-2 cm longer. You may not need to go longer at all.

the lemond has a very slack seat tube. I think it is 72.5...